Glowing objects in the sky, mysterious military reports and files kept under lock and key for decades: newly released UFO documents offer a glimpse into some of the most baffling cases of recent decades.

A key focus of these historical files are reports by Allied pilots from the final months of the Second World War. They described glowing flying objects moving at high speed that accompanied their aircraft over Germany. These phenomena later became known as "Foo Fighters".

In the file (source in German) (source in English), it literally states:

On the night of 22 December 1944, two lights rose from the ground near an aircraft of the 415th Night Fighter Squadron, climbed to its altitude, took up position behind its tail for about two minutes and then 'peeled away again' – according to the crew, always under 'complete control'. Ground radar confirmed that there were no enemy aircraft in the vicinity.

Such encounters were reported repeatedly. Over a period of six weeks, crews of the 415th over Germany and France spoke of red, green, orange and amber-coloured lights that flew in formation with their aircraft, carried out evasive manoeuvres and came as close as around 30 metres. The pilots called these phenomena "Foo Fighters".